Toothbrushes provide many oral hygiene benefits, including removal of plaque, food, and debris to help avoid tooth decay and disease. They remove stained pellicle from the surface of each tooth to help whiten the teeth. The bristles combined with the brushing motion also massage the gingival tissue for stimulation and increased tissue health.
Powered toothbrushes have been available for some time. Powered toothbrushes have advantages over manual (non-powered) toothbrushes in that they impart movement to the bristles at much higher speeds than possible manually. They also may impart different types and directions of motion. These motions, in combination with manual movement of the toothbrush by the user, generally provides superior cleaning than manual toothbrushes. Typically, powered toothbrushes are powered by disposable or rechargeable batteries that power an electric motor, which in turn drives the toothbrush head.
Known powered toothbrushes include a brush head with a bristle carrier portion that rotates, oscillates or vibrates in some manner so as to clean the teeth. The bristles, which typically comprise bristle tufts, are generally uniform with one end fixed into the bristle carrier portion and the other end free to contact the surface of the teeth while brushing. The free ends of the various tufts present a surface envelope that is capable of some deformation when the bristles bend. When in contact with the surface to be brushed, the bristles may deform so that the surface envelope tends to conform to the complex surface of the teeth. Human teeth generally lie in a “C” shaped curve within the upper and lower jaw, and each row of teeth consequently has a convex outer curve and a concave inner curve. Individual teeth often have extremely complex surfaces, with areas that may be flat concave, or convex. The more precise conformation between the bristles and the tooth surface, the more effective the toothbrush may be in cleaning, whitening and/or stimulating.
Conventional electric toothbrushes provide limited bristle movement in one or two dimensions. For example, known toothbrushes may include circular or cylindrical brush heads that move rotationally in a clockwise and counterclockwise reciprocating movement. Additionally, other known toothbrushes provide up and down bristle movement parallel to the toothbrush body, or back and forth movement perpendicular to the toothbrush body. While these designs enhance traditional manual brushing, they are limited in the engagement between the bristles and the teeth. Moreover, two dimensional movement of the bristles may cause pinching of the gums, or other discomfort or irritation. Therefore, an electric toothbrush with improved brush head movement is needed in the art to provide better and more comfortable teeth cleaning.